On the evolution of viviparity and egg-guarding in squamate reptiles: A reply to R. Shine and M. S. Y. Lee

In a precedent paper (de Fraipont ct al., 1996), we analyzed the transition s between oviparity egg-guarding, and viviparity using McClade. These analy ses were criticized on both the phylogenies and the methods used. We redid the analyses using only clades where the three modes of reproduction were p resent. and using a new maximum likelihood-based statistical technique. Alt hough only relevant to thr clades studied. the results supported our previo us view that egg-guarding and viviparity are seemingly independent evolutio nary events, and that oviparity may evolve back from viviparity.